Are you in an area with a good signal? Are you connected to RIM? Are you getting any sort of error message?

Have you tried a battery pull? That is the first thing you should do when you have any problem. With the device on, remove the battery for about 30 seconds, replace and let the device reboot. Then see if email works.

If not, then reregister using the host routing tables, which will reregister your device with Sprint and resend the service books. If that doesn't work, then call the carrier's tech support. they could be having a data/tower outage in your area.

Did all of the above before this post. On the phone with Sprint now. Going to try and resend service books. Thanks guys!